Messages in this thread Patch in this message | | | Date | Mon, 18 Mar 2013 22:47:41 -0700 | Subject | Re: [PATCH 1/3] mm, nobootmem: fix wrong usage of max_low_pfn | From | Yinghai Lu <> |
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On Mon, Mar 18, 2013 at 10:15 PM, Joonsoo Kim <iamjoonsoo.kim@lge.com> wrote: > max_low_pfn reflect the number of _pages_ in the system, > not the maximum PFN. You can easily find that fact in init_bootmem(). > So fix it.
I'm confused. for x86, we have max_low_pfn defined in ...
#ifdef CONFIG_X86_32 /* max_low_pfn get updated here */ find_low_pfn_range(); #else num_physpages = max_pfn;
check_x2apic();
/* How many end-of-memory variables you have, grandma! */ /* need this before calling reserve_initrd */ if (max_pfn > (1UL<<(32 - PAGE_SHIFT))) max_low_pfn = e820_end_of_low_ram_pfn(); else max_low_pfn = max_pfn;
and under max_low_pfn is bootmem.
> > Additionally, if 'start_pfn == end_pfn', we don't need to go futher, > so change range check. > > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> > > diff --git a/mm/nobootmem.c b/mm/nobootmem.c > index 5e07d36..4711e91 100644 > --- a/mm/nobootmem.c > +++ b/mm/nobootmem.c > @@ -110,9 +110,9 @@ static unsigned long __init __free_memory_core(phys_addr_t start, > { > unsigned long start_pfn = PFN_UP(start); > unsigned long end_pfn = min_t(unsigned long, > - PFN_DOWN(end), max_low_pfn); > + PFN_DOWN(end), min_low_pfn);
what is min_low_pfn ? is it 0 for x86?
Thanks
Yinghai
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